The World Meteorological Organization approved a list of 21 Atlantic storm names for the 2020 season. AccuWeather reports there are, on average, 12 named storms in a full season, but at this point, there's only one of the 21 that has gone unused. That would be Wilfred, reports USA Today, which notes there are currently four named systems at play: Paulette, Sally, Teddy, and Vicky. But the National Hurricane Center was as of Tuesday also tracking three potential weather systems. If one of those becomes Wilfred, we'll then switch to a new alphabet: the Greek one. It wouldn't be unprecedented. In 2005 we ended up using six Greek names: Alpha, Beta, Gamma, Delta, Epsilon, and Zeta. We'd use them in that order again; there are 24 in total on that list.
But as the Washington Post explains, some meteorologists aren't fans of this approach. That's because we use six rotating sets of names, and when named storms end up being particularly deadly or damaging, their names are retired. Katrina and Sandy, for instance, are off the lists, with Katia and Sara being subbed in. There aren't replacements for the Greek alphabet, though, and some say it would be weird to skip a letter. The WMO's solution: If a major storm designated by a Greek letter is retirement-worthy, it will be included in the official list of retired storms, along with its year, but the letter will still be available for future use. One other proposal on the table: introducing a seventh list of names to be used as "extras." As for why there are 21 names on the six rotating lists and not 26, AccuWeather explains Q, U, X, Y, and Z aren't used due to the slim number of names that begin with those letters. (Read more hurricane stories.)